We have studied model gold catalysts consisting of gold clusters supported on planar titania supports and Au single crystalline samples employing standard UHV surface chemical probes in addition to molecular beam techniques. In this talk I will focus on our results relating to enhanced CO oxidation by adsorbed water and the oxidation of alcohols employing single crystalline bulk gold. Briefly, we have found that adsorbed water can greatly enhance CO oxidation on oxygen pre-covered bulk gold at low temperatures. Additionally, we have found that atomic oxygen pre-covered Au(111) can partially oxidize ethanol, 1- and 2-propanol, and 2-butanol to their respective ketone or aldehyde with high efficiency and selectivity.